The subject matter disclosed herein relates to motor control and, in particular, to controlling multiple motors in a multi-motion system during times of reduced power or grid fluctuation.
A typical motor control system includes a power converter that converts power from a power source (typically after being stepped down by a transformer) into an intermediate form and provides it to an intermediate link. A motor driver utilizes the power from the intermediate link to control, for example, the operation of an electric motor. In particular, the motor driver (typically implemented as an inverter or chopper) transforms the fixed voltage or current source or link power to a variable frequency and magnitude voltage or current for supply to a motor driving a load.
The power flow from or to the power source is limited by factors such as the impedance between the power source and the power converter, the voltage of the power source during operation, the temperature of the power converter and the instantaneous capability thereof as well as the voltage capability (constraints) of the power converter and the power source.
It has been discovered that fluctuations or reductions in the power from the power source may commonly exist and are beyond of the control of the motor control system. These situations may lead a situation where the intermediate link collapses. Such a collapse may cause the motors to become inoperable and require a restart.